The research proposed involves molecular characterization of binding proteins active in the transport of small molecules into prokaryotic cells. The synthesis, processing and eventual fate of periplasmic binding proteins will be considered. We have already established that a larger, unprocessed form of the arabinose binding protein exists, and are proceeding with a sequence analysis of the signal region. Where and how the molecule is processed is of considerable interest as well as the fate of such periplasmic proteins when they are no longer required. The former will be pursued using isolated membrane fragments and affinity chromatography and the latter using polyacrylamide gel electrophoresis and antigenic responses. Precisely how binding proteins function and interact in multicomponent transport processes will be considered using sequence analyses of the sulfate and histidine binding proteins and several functionally defective arabinose binding proteins isolated from mutants incapable of in vivo high affinity L-arabinose uptake. Genetic characterization of the ara F locus will be undertaken as well as genetic and biochemical studies of the proposed membrane interaction site.